You can send an immediate test without waiting for the delay periods by using the Send Test Email(s) button in:

Using the Send Test Email(s) button on the Cart Layout page sends all stages of the selected trigger using the chosen cart layout.

Example:

If you have a three-stage cart abandonment trigger, each using a different layout (Layout 1 for stage 1, Layout 2 for stage 2, and so on), and you are currently looking at Layout 1, when you do a test send, you will receive three emails, each using Layout 1 for the cart layout.

Learn more in Test a trigger.